Spectrophotometer cells with micro capacities (0. The narrower walls enables smaller sample sizes. Features of FireflySci Type 18 Micro Spectrophotometer Cuvette: Highly accurate results, only need to. ST1818 is a new portable spectrophotometer with 3nh own core research and development technology,Built-in large area silicon photodiode array (double row 18 groups) sensors, with excellent repeatability and inter-station differences, measuring data continued stable, accurate and reliable. With large measuring range (190 nm to 1100 nm) and narrow spectral bandwidth (2 nm). The FireflySci Type 18M Micro Cuvette is a modified version of the Type 18 but with black walls for blocking out stray light.